Adjustable ground speed control devices, systems, and methods for walk-behind equipment

ABSTRACT

The present subject matter relates to adjustable ground speed control devices, systems, and methods for walk-behind equipment. A variable speed control system for a machine can include a control system base, one or more control lever selectively movable with respect to the control system base between a first operating position and a second operating position, first and second speed adjustment actuators positioned on the control system base proximal to the one or more control lever, and a control unit configured for communication with the one or more control lever, the first and second speed adjustment actuators, and a machine component. In this configuration, the one or more control lever can be configured to control the machine component to operate between a minimum operating speed and a variable maximum operating speed, where the value of the variable maximum operating speed can be adjusted by the first and second speed adjustment actuators.

TECHNICAL FIELD

The subject matter disclosed herein relates generally to variablecontrol systems for powered equipment. More particularly, the subjectmatter disclosed herein relates to variable speed controls and methodsfor walk-behind working machines, such as lawnmowers.

BACKGROUND

Many walk-behind working machines, such as lawnmowers and other similarsmall powered equipment, have a self-propel system that propels ordrives the working machine at a selected ground speed. In such systems,a control system is typically carried on the handle to allow theoperator to engage and disengage the self-propel system and to select adesired ground speed. For example, many such control systems use apivotable ground speed control bail on the handle of the workingmachine. Generally, self propelled drive systems can be divided into twocategories: single/multiple speed, and variable speed. Insingle/multiple speed drive systems, the ground speed is fixed by one ormore gear ratios, and it can only be adjusted by selecting a differentgearset (if available). In contrast, variable speed drive systems allowthe operator the ability to “infinitely” adjust the ground speed of thelawn mower, such as by a slipping belt system where the belt tension isvaried, a slipping clutch system where the clutch pressure is varied, ahydrostatic transmission where a swash plate angle is variable, or anelectric drive system where the electric power supply is switched.

Even in such variable speed drive systems, however, the maximumoperating speed is either fixed or, if variable, cumbersome to changewhile the working machine is being operated. Specifically, in allcurrently available adjustable control drive systems, the maximum speedsetting is made by a mechanical lever, rotary knob, or mechanicallatching device. In such configurations, an operator must remove atleast one of his hands from the control handle to make any adjustmentsto the maximum operating speed. Accordingly, making such adjustments canresult in the operator at least partially losing some degree of controlover the working machine. In view of these issues, it would be desirablefor a ground speed control system to allow for adjustment of the maximumspeed setting of the working machine without diminishing the operator'sability to control the working machine.

SUMMARY

In accordance with this disclosure, adjustable ground speed controldevices, systems, and methods for walk-behind equipment are provided. Inone aspect, a variable speed control system for a walk-behind workingmachine is provided. The variable speed control system can include acontrol system base, one or more control lever that is selectivelymovable with respect to the control system base between a firstoperating position and a second operating position, first and secondspeed adjustment actuators positioned on the control system baseproximal to the one or more control lever, and a control unit configuredfor communication with the one or more control lever, the first andsecond speed adjustment actuators, and a machine component. In thisconfiguration, the control unit can be configured to selectively controlthe operation of the machine component between a minimum operating speedand a variable maximum operating speed, the variable maximum operatingspeed having a variable value, where the first speed adjustment actuatorcan be configured to increase the value of the variable maximumoperating speed (e.g., up to a system maximum speed), and the secondspeed adjustment actuator can be configured to decrease the value of thevariable maximum operating speed. The one or more control lever can beconfigured to control the machine component to operate at the minimumoperating speed when the one or more control lever is in the firstangular position, and the one or more control lever can be configured tocontrol the machine component to operate at the variable maximumoperating speed when the one or more control lever is in the secondangular position.

In another aspect, a method for varying a speed of a walk-behind workingmachine is provided. The method can include moving one or more controllever with respect to a control system base between a first operatingposition and a second operating position and, without releasing the oneor more control lever, selectively actuating one of a first speedadjustment actuator or a second speed adjustment actuator positioned onthe control system base proximal to the one or more control lever. Inthis way, pivoting the one or more control lever to the first operatingposition can control a machine component to operate at a minimumoperating speed, whereas pivoting the one or more control lever to thesecond operating position can control the machine component to operateat a variable maximum operating speed, wherein a value of the variablemaximum operating speed is variable. Further, actuating the first speedadjustment actuator can increase the value of the variable maximumoperating speed, and actuating the second speed adjustment actuator candecrease the value of the variable maximum operating speed.

Although some of the aspects of the subject matter disclosed herein havebeen stated hereinabove, and which are achieved in whole or in part bythe presently disclosed subject matter, other aspects will becomeevident as the description proceeds when taken in connection with theaccompanying drawings as best described hereinbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the present subject matter will be morereadily understood from the following detailed description which shouldbe read in conjunction with the accompanying drawings that are givenmerely by way of explanatory and non-limiting example, and in which:

FIG. 1a is a perspective view of a variable speed control system in afirst operating position according to an embodiment of the presentlydisclosed subject matter;

FIG. 1b is a perspective view of a variable speed control system in asecond operating position according to an embodiment of the presentlydisclosed subject matter;

FIG. 2 is a schematic representation of a drive system for aself-propelled machine according to an embodiment of thepresently-disclosed subject matter;

FIG. 3 is a block diagram illustrating a system for adjusting a maximumoperating speed of a self-propelled machine according to one aspect ofthe subject matter described herein; and

FIG. 4 is a front view of a variable speed control system according toan embodiment of the presently disclosed subject matter.

DETAILED DESCRIPTION

The present subject matter provides variable speed control systems andmethods for walk-behind working machines, such as lawnmowers and similarpowered machines. In one aspect, the present subject matter providesvariable speed control systems and methods that can vary speed,comfortably hold a fixed speed, and vary the maximum speed at which theworking machine is operated.

Specifically, for instance, as shown in FIGS. 1a through 2, a variablespeed control system, generally designated 100 can comprise a handle 110configured to be gripped by an operator to control the operation of aworking machine, such as a lawnmower or other small powered machine, towhich handle 110 is connected. A control system base 120 can be attachedto or otherwise positioned near handle 110. A display 122 can beprovided on control system base 120 to provide warnings or otherindications of the operating state of the working machine, and an engineengagement control 124 (e.g., a push-button starter). A pair of controllevers, generally designated 130 a and 130 b, can be movably attached tocontrol system base 120. With this general configuration, control levers130 a and 130 b can be moved to control operation of a machinecomponent, such as for example a variable transmission for a self-propelsystem of the working machine.

In particular, a first control lever 130 a can comprise a first leverarm 132 a having a first end that is pivotably attached to controlsystem base 120 (e.g., about a pivot axis that extends through controlsystem base 120) and a second end substantially opposing the first endthat comprises a first grip portion 134 a. Likewise, a second controllever 130 b can comprise a second lever arm 132 b having a first endthat is pivotably attached to control system base 120 and a second endsubstantially opposing the first end that comprises a second gripportion 134 b. Specifically, for example, as shown in FIGS. 1a and 1 b,each of first and second control levers 130 a and 130 b can have asubstantially L-shaped profile, with first and second grip portions 134a and 134 b extending at a non-zero angle (e.g., between about 50 and 90degrees) away from first and second lever arms 132 a and 132 b,respectively. This angular arrangement allows the operator to grab oneor both of first or second grip portions 134 a or 134 b in a comfortablehand position and pivot first and second control levers 130 a and/or 130b with respect to control system base 120. In some embodiments, firstand second lever arms 132 a and 132 b can be coupled for rotationtogether, whereby pivoting of one of first or second lever arms 132 a or132 b (e.g., by pressing on a respective one of first and second gripportions 134 a or 134 b) causes a corresponding movement of the other.Alternatively, first and second lever arms 132 a and 132 b can beindependently movable with respect to control system base 120 such thatthe operation of either (or both) of first and second lever arms 132 aand 132 b can be moved to control operation of a machine component.

In this regard, to control the operation of the associated machinecomponent (e.g., a self-propel system), first and second control levers130 a and 130 b can be selectively pivoted with respect to controlsystem base 120 between a first angular position (See, e.g., FIG. 1a )at which first and second grip portions 134 a and 134 b of first andsecond control levers 130 a and 130 b are spaced apart from handle 110and a second angular position (See, e.g., FIG. 2b ) at which first andsecond grip portions 134 a and 134 b are drawn against handle 110.Further in this regard, in some embodiments, when in the secondposition, at least a portion of each of first and second grip portions134 a and 134 b is positioned within a recess that is formed in an edgeof handle 110.

In any configuration, the movement of first and second control levers130 a and 130 b between the first and second angular position caninvolve pivoting the control lever through a limited angular range(e.g., about 35 degrees) such that the movement of first and secondcontrol levers 130 a and 130 b can be comfortably performed by theoperator without letting go of handle 110. In other words, while theoperator is holding handle 110 to steer or otherwise control the workingmachine, the operator can extend his/her thumbs and/or palms backwards ashort distance (e.g., about 71 mm) to grab one or both of first andsecond grip portions 134 a and 134 b while keeping his/her other fingerson handle 110.

Further in this regard, a first speed adjustment actuator 140 a and asecond speed adjustment actuator 140 b can also be provided on controlsystem base 120. First and second speed adjustment actuators 140 a and140 b can be used in combination with first and second control levers130 a and 130 b to further control the operating state of the workingmachine. In the configuration shown in FIGS. 1a and 1 b, for example,first and second speed adjustment actuators 140 a and 140 b can comprisepush buttons positioned proximal to first and second control levers 130a and 130 b, respectively. In this arrangement, an operator can easilyreach and depress the push buttons while holding handle 110 and/or firstand second control levers 130 a and 130 b. In particular, first andsecond speed adjustment actuators 140 a and 140 b can be positionedadjacent to a natural thumb position of an operator when the operator ismanipulating first and second control levers 130 a and 130 b. In theconfiguration shown in FIGS. 1a and 1 b, for example, such a positioningresults in first speed adjustment actuator 140 a being positioned at ornear a right-most edge of control system base 120 such that it is nearto first control lever 130 a, and second speed adjustment actuator 140 bis positioned at or near a left-most edge of control system base 120such that it is near to second control lever 130 b. Alternatively, firstand second speed adjustment actuators 140 a and 140 b can be provided inany of a variety of other forms, including by not limited to a tactileswitch, a capacitance sensor, a membrane with capacitance sensing, orany other device that is sensitive to touch. In any configuration,variable speed control system 100 can be designed to be easilymanipulated while the operator maintains overall control of the workingmachine.

In operation, where the machine component is a self-propel system for aworking machine, moving first and second control levers 130 a and 130 bto the first angular position can control the machine to be in a firstoperating state, which can be a minimum operating speed or a disengagedstate (i.e., no torque applied). Conversely, upon movement of first andsecond control levers 130 a and 130 b to the second angular position,the machine component can be controlled to be in a second operatingstate. Again, for instance, where the machine component is a self-propelsystem for a working machine, the second operating state can be a fullyengaged or high speed state (i.e., torque applied to the drive systemsuch that the working machine is moved at a selected cruising speed).

Furthermore, those having skill in the art will recognize that first andsecond control levers 130 a and 130 b can additionally be pivoted to anyof a variety of intermediate angular positions to correspondinglyoperate the machine component in one or more partial engagement states(e.g., low- to medium-speed operating states of the self-propel system).In this way, the operator can selectively operate the machine componentat states between the first and second operating states. For example,where the machine component is a self-propel system, positioning firstand second control levers 130 a and 130 b at a selected intermediateposition can control the self-propel system to operate at a speed thatis proportional to the relative angular travel of first and secondcontrol levers 130 a and 130 b between the first and second operatingstates. At any position, however, first and second control levers 130 aand 130 b can be configured to be comfortably held and manipulated bythe operator while maintaining a grip on handle 110.

Furthermore, first and second speed adjustment actuators 140 a and 140 bcan provide additional control over the range of operating statesavailable. In particular, first and second speed adjustment actuators140 a and 140 b can be configured to adjust the value of a parameter ofthe output at the second operating state of the machine component.Again, in the case where the machine component is a self-propel systemfor a working machine, for example, this adjustment allows the maximumoperating speed setting of the self-propel system to be adjusted basedon the preferences of the operator.

In one embodiment, for example, first speed adjustment actuator 140 acan be operable to change the maximum operating speed setting of theself-propel system to have an incrementally higher value, whereas secondspeed adjustment actuator 140 b can be operable change the maximumoperating speed setting of the self-propel system to have adecrementally lower value. In this way, fine adjustments of the maximumoperating speed setting of the working machine can be made withoutdiminishing the operator's ability to control the working machine.

The control inputs from first and second control levers 130 a and 130 band first and second speed adjustment actuators 140 a and 140 b can thenbe communicated to the operation of the working machine. In someembodiments, for example, the working machine can utilize a hybridsystem, such as is illustrated in FIG. 2, in which the working element(e.g., a blade when working machine is a lawn mower) is driven by acombustion engine, generally designated 150, and the self propelleddrive system, generally designated 160, is driven by an electric motor162 that is configured to supply power to one or more wheels 164 of theself-propelled machine at a selected forward ground speed. Drive system160 can be mechanically driven by engine 150 directly, or as shown inFIG. 2, drive system 160 can be electrically driven, and the operationof drive system 160 can be controlled by the operation of a control unit200 (e.g., an electronic control unit (ECU)) that is in communicationwith both engine 150 and variable speed control system 100.

In some aspects, for example, drive system 160 can comprise an electrictransmission, and electric motor 162 can be an electric transmissionmotor that is powered using an electrical actuator or generator 155 orany other type of rotating object (and/or a battery where engine 150 isnot running). In some aspects, electrical actuator or generator 155 canbe coupled and/or mounted onto a crankshaft of engine 150. Electricmotor 162 can be adapted to directly power drive system 160, and drivesystem 160 can be adapted to transfer and/or supply power directly tothe one or more wheels 164 of the self-propelled machine.

As discussed above, variable speed control system 100 can be configuredto be operable by an operator to select a desired ground speed of theself-propelled machine. In particular, the desired ground speed can beselectively chosen by the operator through manipulation of variablespeed control system 100, such as by moving first and second controllevers 130 a and 130 b to any of a range of operating positionscorresponding to one of a predetermined range of desired ground speeds.This operability advantageously allows an operator to choose a groundspeed that best suits the terrain and/or the operator's mobility, amongother factors. Furthermore, the value of the cruising/maximum operatingspeed corresponding to the second angular position of first and secondcontrol levers 130 a and 130 b (i.e., fully-depressed against handle110) can be adjusted up or down by operating first and second speedadjustment actuators 140 a and 140 b. In this way, users who desire tooperate the self-propelled machine at lower speeds do not need tocarefully hold first and second control levers 130 a and 130 b at anunstable intermediate operating position between the fully disengagedand fully engaged states. Rather, such users can simply change themaximum operating speed setting using first and second speed adjustmentactuators 140 a and 140 b, and then move first and second control levers130 a and 130 b to the fully engaged position. This adjustability thusallows the operator to pick a maximum operating speed that can be easilyand consistently achieved without continuously adjusting the position offirst and second control levers 130 a and 130 b.

In this way, the desired ground speed can be selected by the operator,with variable speed control system 100 being configured to transmit theselected desired ground speed, in the form of a signal or pulse, todrive system 160 via control unit 200. For example, variable speedcontrol system 100 can be configured to transmit an electrical signal orpulse (e.g. a control signal) to control unit 200 by way of anelectrical sensor. Variable speed control system 100 can alternativelybe configured to transmit a digital or analog signal to control unit200, while other alternative means of communication can also beutilized. In one aspect, the control signal can communicate the desiredground speed to control unit 200 essentially as a ratio of the desiredground speed compared to a system maximum ground speed setting (e.g.,which can be equal to or greater than the user-defined maximum operatingspeed setting controlled by first and second speed adjustment actuators140 a and 140 b). Under normal operating conditions, control unit 200can be configured to control drive system 160 to drive theself-propelled machine at the desired ground speed selected by way ofvariable speed control system 100.

Control unit 200 can correspondingly be configured to receive thecontrol signal from variable speed control system 100. Based at leastpartly on this input, control unit 200 can transmit power to drivesystem 160 via electric motor 162, thereby controlling the transmissionspeed or actual ground speed of the self-propelled machine (e.g., bydriving wheels 164). For example, control unit 150 can be configured sothat the control signal can be transmitted as a signal or pulse to amicrocontroller 210. In one aspect, engine power can be communicated tocontrol unit 200 as alternating current or AC power. Where engine 150 isconfigured to communicate AC power to control unit 200, then controlunit 200 must convert AC power to DC power before reaching electricmotor 162. In one aspect, for example, engine 150 transmits power to arectifier 202 or any other device that converts alternating current (AC)to direct current (DC). After power has been converted from AC power toDC power, a DC power bus 204 can communicate said power in the form of asignal or pulse to a power delivery system, generally designated 206, inorder to control the power supplied to electric motor 162. Powerdelivery system 206 can comprise that of a pulse width modulator or(PWM), a potentiometer, or a rheostat.

In one particular configuration, for example, the control inputs fromfirst and second speed adjustment actuators 140 a and 140 b can becommunicated to and interpreted by control unit 200 in the process shownin FIG. 3. As illustrated in FIG. 3, actuation of first speed adjustmentactuator 140 a can communicate a speed increase signal 302 a to controlunit 200, whereas actuation of second speed adjustment actuator 140 bcan communicate a speed decrease signal 302 b to control unit 200. Aninput reception step 310 can thus include control unit 200 receivingthese inputs, and a comparison step 320 can include identifying whetherone of speed increase signal 302 a or speed decrease signal 302 b isbeing communicated. Specifically, control unit 200 can test whether aspeed increase is requested (e.g., in a speed increase comparison step322 a) or a speed decrease is requested (e.g., in a speed decreasecomparison step 322 b). In some embodiments, a double-input check 312can be performed before comparison step 320 to avoid unnecessary changesin the maximum operating speed setting when both of first and secondspeed adjustment actuators 140 a and 140 b are operated simultaneously.

When only a single input is provided, however, if a speed increase isrequested (i.e., speed increase comparison step 322 a returns a truevalue), control unit 200 can further determine whether increasing themaximum operating speed setting would cause the system to exceed asystem maximum setpoint (e.g., manufacturer-set maximum speed) in amaximum comparison step 330 a. If an increase would not exceed thesystem maximum setpoint, a speed increment step 340a can increase themaximum operating speed setting. If the maximum operating speed settingalready equals the system maximum setpoint, no change is made.

Alternatively, if a speed decrease is requested (i.e., speed decreasecomparison step 322 b returns a true value), control unit 200 canfurther determine whether decreasing the maximum operating speed settingwould cause the system to fall below an established system minimumsetpoint in a minimum comparison step 330 b. If a decrease would notbring the system below this value, a speed decrement step 340 b candecrease the maximum operating speed setting. If the maximum operatingspeed setting is already at the system minimum setpoint, no change ismade.

The maximum operating speed established by this or by another processcan be displayed to the operator to identify the current setpoint atwhich the working machine is operating and to provide visual feedback tothe operator with respect to how the actuation of first and second speedadjustment actuators 140 a and 140 b affect the maximum operating speedsetting. As shown in FIG. 4, for example, a speed setting indicator 123can be provided on display 122 to graphically indicate the currentsetpoint of the maximum operating speed within the range of possiblevalues (e.g., between a system minimum setpoint and a system maximumsetpoint discussed above). In this regard, speed setting indicator 123can be provided as one of an LED display, and LCD display, an array ofindicator lights, or any of a variety of other display devices known tothose having skill in the art as being able to convey a value and/orrelative speed setting within a given range.

In some aspects, the subject matter described herein may be implementedin software in combination with hardware and/or firmware. For example,the subject matter described herein may be implemented in softwareexecuted by a processor (e.g., a hardware-based processor),microprocessor, and/or microcontroller of the electronic control unit.In one exemplary implementation, the subject matter described herein maybe implemented using a non-transitory computer readable medium havingstored thereon computer executable instructions that when executed bythe processor of a computer control the computer to perform steps.Exemplary computer readable media suitable for implementing the subjectmatter described herein include non-transitory devices, such as diskmemory devices, logic devices, logic transistors, chip memory devices,programmable logic devices, such as field programmable gate arrays, andapplication specific integrated circuits. In addition, a computerreadable medium that implements the subject matter described herein maybe located on a single device or computing platform or may bedistributed across multiple devices or multiple computing platforms.

The present subject matter can be embodied in other forms withoutdeparture from the spirit and essential characteristics thereof. Theembodiments described therefore are to be considered in all respects asillustrative and not restrictive. Although the present subject matterhas been described in terms of certain preferred embodiments, otherembodiments that are apparent to those of ordinary skill in the art arealso within the scope of the present subject matter.

What is claimed is:
 1. A variable speed control system for a walk-behindworking machine, the system comprising: a control system base; one ormore control lever selectively movable with respect to the controlsystem base between a first operating position and a second operatingposition; first and second speed adjustment actuators positioned on thecontrol system base proximal to the one or more control lever; and acontrol unit configured for communication with the one or more controllever, the first and second speed adjustment actuators, and a machinecomponent; wherein the control unit is configured to selectively controlthe operation of the machine component between a minimum operating speedand a variable maximum operating speed; wherein the first speedadjustment actuator is configured to communicate with the control unitto increase a value of the variable maximum operating speed; wherein thesecond speed adjustment actuator is configured to communicate with thecontrol unit to decrease the value of the variable maximum operatingspeed; and wherein the one or more control lever is configured tocommunicate with the control unit to control the machine component tooperate at the minimum operating speed when the one or more controllever is in the first operating position, and wherein the one or morecontrol lever is configured to control the machine component to operateat the variable maximum operating speed when the one or more controllever is in the second operating position.
 2. The variable speed controlsystem of claim 1, wherein the machine component comprises a variabletransmission for a self-propel system of the working machine; whereinthe minimum operating speed comprises a disengaged state of the machinecomponent; and wherein the variable maximum operating speed comprisesoperation of the self-propel system at a cruising speed defined by thevalue of the variable maximum operating speed.
 3. The variable speedcontrol system of claim 1, wherein the one or more control levercomprises: a first control lever selectively movable with respect to afirst side of the control system base, wherein the first speedadjustment actuator is positioned proximal to the first control lever;and a second control lever selectively movable with respect to a secondside of the control system base, wherein the second speed adjustmentactuator is positioned proximal to the second control lever.
 4. Thevariable speed control system of claim 3, wherein the first controllever and the second control lever are coupled for movement togetherwith respect to the control system base.
 5. The variable speed controlsystem of claim 1, wherein the first and second speed adjustmentactuators each comprise a device selected from the group consisting of apush button, a tactile switch, a capacitance sensor, and a membrane withcapacitance sensing.
 6. The variable speed control system of claim 1,wherein the control unit is configured to selectively control theoperation by controlling a power delivery system connected to themachine component.
 7. A variable speed control system for a walk-behindworking machine, the system comprising: a control system base; first andsecond control levers selectively pivotable with respect to the controlsystem base between a first angular position and a second angularposition; a first speed adjustment actuator positioned on the controlsystem base proximal to the first control lever; a second speedadjustment actuator positioned on the control system base proximal tothe second control lever; a control unit configured for communicationwith the first and second control levers, the first and second speedadjustment actuators, and a machine component; wherein the control unitis configured to selectively control the operation of the machinecomponent between a minimum operating speed and a variable maximumoperating speed; wherein the first speed adjustment actuator isconfigured to communicate with the control unit to increase a value ofthe variable maximum operating speed; wherein the second speedadjustment actuator is configured to communicate with the control unitto decrease the value of the variable maximum operating speed; andwherein the first and second control levers are configured tocommunicate with the control unit to control the machine component tooperate at the minimum operating speed when at least one of the firstand second control levers is in the first angular position, and whereinthe first and second control levers are configured to control themachine component to operate at the variable maximum operating speedwhen at least one of the first and second control levers is in thesecond angular position.
 8. The variable speed control system of claim7, wherein the machine component comprises a variable transmission for aself-propel system of the working machine; wherein the minimum operatingspeed comprises a disengaged state of the machine component; and whereinthe variable maximum operating speed comprises operation of theself-propel system at a cruising speed defined by the value of thevariable maximum operating speed.
 9. The variable speed control systemof claim 7, wherein the first control lever and the second control leverare coupled for movement together with respect to the control systembase.
 10. The variable speed control system of claim 7, wherein thefirst and second speed adjustment actuators each comprise a deviceselected from the group consisting of a push button, a tactile switch, acapacitance sensor, and a membrane with capacitance sensing.
 11. Thevariable speed control system of claim 7, wherein the control unit isconfigured to selectively control the operation by controlling a powerdelivery system connected to the machine component.
 12. A method forvarying a speed of a walk-behind working machine, the method comprising:moving one or more control lever with respect to a control system basebetween a first operating position and a second operating position;without releasing the one or more control lever, selectively actuatingone of a first speed adjustment actuator or a second speed adjustmentactuator positioned on the control system base proximal to the one ormore control lever; wherein moving the one or more control lever to thefirst operating position controls a machine component to operate at aminimum operating speed; wherein moving the one or more control lever tothe second operating position controls the machine component to operateat a variable maximum operating speed; wherein actuating the first speedadjustment actuator increases the value of the variable maximumoperating speed; and wherein actuating the second speed adjustmentactuator decreases the value of the variable maximum operating speed.13. The method of claim 12, wherein the machine component comprises avariable transmission for a self-propel system of the working machine;wherein controlling the machine component to operate at the minimumoperating speed comprises operating the machine component in adisengaged state; and wherein controlling the machine component tooperate at the variable maximum operating speed comprises operating theself-propel system at a cruising speed defined by the value of thevariable maximum operating speed.
 14. The method of claim 12, whereinmoving one or more control lever with respect to a control system basecomprises pivoting a lever arm of at least one of the one or morecontrol lever, the lever arm being pivotably coupled to the controlsystem base; wherein moving the one or more control lever to the firstoperating position comprises pivoting the lever arm to a first angularposition relative to the control system base; and wherein moving the oneor more control lever to the second operating position comprisingpivoting the lever arm to a second angular position relative to thecontrol system base.
 15. The method of claim 12, wherein actuating oneof a first speed adjustment actuator or a second speed adjustmentactuator comprises pushing a push button or touching one of a tactileswitch, a capacitance sensor, or a membrane with capacitance sensing.16. The method of claim 12, wherein moving the one or more control leverwith respect to a control system base comprises moving at least one of afirst control lever selectively movable with respect to a first side ofthe control system base or a second control lever selectively movablewith respect to a second side of the control system base; and whereinselectively actuating one of a first speed adjustment actuator or asecond speed adjustment actuator comprises selectively activating one ofthe first speed adjustment actuator positioned proximal to the firstcontrol lever or the second speed adjustment actuator positionedproximal to the second control lever.
 17. The method of claim 16,wherein the first control lever and the second control lever are coupledtogether; and wherein moving at least one of the first control lever orthe second control lever results in both of the first control lever andthe second control lever being moved with respect to the control systembase.
 18. The method of claim 12, wherein actuating the first speedadjustment actuator comprises comparing the value of the variablemaximum operating speed to a system maximum setpoint; and increasing thevalue of the variable maximum operating speed by an increment if thevalue of the variable maximum operating speed is less than the systemmaximum setpoint.
 19. The method of claim 12, wherein actuating thesecond speed adjustment actuator comprises comparing the value of thevariable maximum operating speed to a system minimum setpoint; anddecreasing the value of the variable maximum operating speed by adecrement if the value of the variable maximum operating speed isgreater than the system minimum setpoint.
 20. The method of claim 12,wherein moving one or more control lever with respect to a controlsystem base between a first operating position and a second operatingposition varies an output of a power delivery system connected to themachine component.